Eduction device



EDUCTION DEVICE Filed Jan. 6, 1937 w m an OD TR mm MN N H O J 3 G F D mmm Q F m m w w i WA i BY ERIC E SOMMER ATTORNEY Patented Dec. 19, 19392,183,639

UNITED STATES PATENT OFFlCE EDUCTION DEVICE John N. Burclick and Eric E.Sommer, Buffalo,

N. Y., assignors to Carbide and Carbon Chemicals Corporation, acorporation of New York Application January 6, 1937, Serial No. 119,285

11 Claims. (01. 62l) The invention pertains to eduction device when suchan eductor was provided with pluand more particularly to an eductor forremovrality of openings, of which one was the vapor ing a substantiallyuniform composition of a phase at least during a portion of thedischarge, compressed mixture of at least partially liquefied a slowrate or" discharge then discharged only ;;gases of difierent vaportensions from a 0011- gas and this also left an inflammable residue. 5

' tainer in which they are confined under pressure. We have foundhowever that the inflammability An example of such a composition ormixture of the discharged gases or mixture be practi is one containingcarbon dioxide and ethylene cally or entirely eliminated by dischargingthe oxide in the approximate proportion of parts mixture through ajacketed eductcr tube having 10,;of the former to 1 part of the latter.This :naopenings of suitable size and location in both 10- terial ishandled in conventional pressure vesthe mile tube and the outer jacket.sels, for example cylinders such as those used One embodiment of theinvention shown by for the transportation of oxygen, and under theabove-mentioned drawing may comprise an normal conditions the cylindersare approxieductor secured in the inner end of an 15,,mately half fullof the liquid phase of the through a conventional valve B that closes anture which is under about 690 pounds pressure. opening in the upper endof a conventional pres- Due to the widely difierent vapor tensions ofthe sure vessel or cylinder C. The cylinder C in two components thevapor phase is largely carhe of the type usually employed. c bon dioxidewhile the liquid phase is a mixture oxygen under high pressure and thevalve B may 2 of the two components having a higher ethylene beremovably secured in the upper end or neck oxide content than theaverage of the entire thereof by suitable interfitting threads in aconcontent of the cylinder. ventional manner.

The mixture under discussion is used as a The eductor A may be disposedvertically withfumigant and under some conditions one cylinder in thecylinder C and extend from the valve 13 may be used for severalfumigation operations. downward substantially to the bottom, and the 25To be most effective and free from fire hazard upper end of the eductormay be secured to the the proportion of the mixture used for each valveB in a suitable manner. For example, a fumigation should besubstantially that of the suitable portion ill of the upper end of thetubular entire content of the cylinder. Therefore, one eductoi A may bedisposed in a suitable recess 12 of the objects or the invention toprovide an in the lower end of the valve B and the joint 30 eductor tubethat will remove a substantially between the eductor and the valve maybe closed uniform proportion of a compressed mixture of and furthersecured by suitable means such as a plurality of partially liquefiedgases having solder. Thus the upper end of the fluid passage differentvapor tensions from a cylinder in which through the eductor may beconnected with the it is contained. Other aims, objects, and novel innerend of the outlet passage through the 35 features may be obtained fromthe following valve B. description and the accompanying drawing in Thisimproved educt'or may comprise an inner which: tube M which may besurrounded by jacke Fig. 1 is a longitudinal section through a cylinorouter tube 5%. These concentric tubes may 40 der having an outlet valveand an eductor atextend from the bottom of the cylinder 0 to 40 tachedthereto. the lower portion of the valve B, but since it Fig. 2 is a Viewin partial section of the eductor has been found desirable to bend theeductor tube and part of the valve shown in Fig. l, and so that thelower end will be disposed in the Fig. 3 is a sectional view of thelower part of lowermost portion of the cylinder, which is near 5 theeductor and a fiat bottomed cylinder showthe side wall, the upperportion of the eductor ing the action of the mixture during withdrawal.may comprise a single tube l8 which is more In an eductor, such as thoseemployed hereeasily bent. Therefore, the upper portion of the tofore,the lower end was closed and the side eductor may consist of a singletube i8 while the 'D V B With Suitable opsningS through Which lowerportion may consist of concentric tubes h contents f the Cylinder W i haed. l4 and Is. The upper tube l8 may be secured 50; When such a tube wasprovided with a single to the lower end of the valve B in the manneropening near the bottom, liquid only was realready described. The innertube l4 may be moved with the result that the residual liquid securedwithin the lower end of the tube 18 by became richer in ethylene oxideuntil an ina fluid-tight joint, and the outer tube or jacket flammablemixturemight be discharged.v Also,, 15 may be secured to the outside ofthe. lower: 55;

tom of the container.

end of tube l8 by a similar joint. In the construction shown, the upperend of tube i6 is enlarged slightly so that it will fit over the lowerend of tube l8 and the joints between the upper tube l8 and the lowertubes Id and It may be further sealed or secured by suitable means suchas a solder of which silver solder is preferred. The lower ends of thetubes l4 and it may be closed by suitable means such as a plug 28secured in the lower end of the inner tube M and a ring 22 secured inthe annular opening between the lower ends of the tubes it and I6. Theseclosures numbers Zll and 22 may also be secured in place by any suitablemeans such as a solder.

The length of the upper tube l3 with respect to the lower tubes I l andIt may vary according to the character of the mixture being dischargedand the location of the tubes i l and it. However, for the mixturedescribed hereinbefore the length of the tubes M and it may be somewhatgreater than half the interior height of the cylinder. Although theconducting capacity or cross-sectional area of the interior of theeductor may vary according to various conditions of usage, excellent:results have been obtained from a tube Hi having an inner chamber 23with a capacity somewhat greater than the capacity of the outlet throughthe valve B, and an outer tube or jacket I6 of such a size that thecapacity of the annular area or outer chamber 26 between the tubes l4and I6 is somewhat greater or about twice the capacity of the chamber23.

The fluid passage through the inner tube l4 may be provided with aninlet adjacent the bot- This inlet may comprise two openings which maybe located in opposite sides of the tube it closely adjacent to bottomwall 20 and have a combined area or capacity substantially equal to theinterior area or capacity of the tube i l. To withdraw a substantiallyuniform mixture of the contained gases at normal rates of discharge theouter tube or jacket I6 may be provided with a plurality of openings inthe outer wall thereof. These openings 25 may be spaced vertically oneabove the other, with the lowermost hole or opening as near the bottomwall 22 as commercially practicable, and the uppermost openings somewhatmore than half the distance between the lower end of the eductor tube Aand the lower end of the valve B.

The openings 25 may have a vertical spacing that is substantiallylogarithmic with the distance between the openings increasing from thebottom upwards. Although the number of openings 25 may vary according tovarious conditions of usage, excellent results have been attained byemploying seven openings, all in the liquid phase of the mixture whenthe cylinder is fully charged, and of such a size that their combinedarea or capacity is somewhat less than the interior area or capacity ofthe tube l4, so that under conditions of normal discharge there is asubstantial pressure drop between the inside and outside of tube It.

The location of the openings 25 may be such that changes in the liquidand vapor phase composition due to changes in liquid and vapor phasevolume, as the cylinder is discharged, are compensated for by more ofthe openings appearing in the vapor phase and thus admitting more vaporphase into the discharge or central tube. The combined area of theopenings 24 in the inner tube I4 may be sufiiciently large to have asmall enough pressure drop to drain either partly or completely theresidue of liquid present in the annular chamber 26 between the innerand outer tubes I4 and I6. At the same time the combined area of theinlets or openings 25 in the jacket or outer tube It may besufiiciently'small to have a large enough pressure drop so that theliquid entering through them cannot completely fill the chamber 26. Inconsequence of this high pressure drop as soon as an opening isuncovered or opened to the vapor phase the vapor phase is forced throughit and mixed with the liquid phase, so that the composition of thedischarge remains substantially uniform.

Fig. 3 shows the condition in the eductor A during normal rates ofdischarge. Here, it will be observed, the pressure drop through theopenings in the tube It is sufficiently low and the pressure dropthrough the opening in the tube I4 is sufiiciently high so that verylittle or no liquid remains in the chamber 26. When a standard cylindercontaining approximately 66 pounds of a mixture of substantially 9 percent ethylene oxide and 90 per cent carbon dioxide is discharged throughthis improved eductor under unfavorable conditions, such as a relativelyhigh temperature of 100 F. and a relatively slow discharge rate of about60 minutes to the contents of the cylinder, the maximum ethylene oxidecontent of the discharged gas is substantially 11.7 per cent. This isbelow the inflammable limit of 12.3 per cent ethylene oxide in an airmixture and is much lower than the ethylene oxide content of thedischarged gas when prior eductor tubes are employed. For example, whenusing a prior three hole eductor tube under the same condition themaximum ethylene oxide content of the discharged gas would be over 20per cent. Therefore, it appears that the present invention achieves adecided advance in the accuracy and safety of devices for eductingmixtures of liquefied gases from cylinders.

Although a preferred embodiment of this invention is disclosed, it willbe clear that this general method of eduction may be applied toapparatus having component parts of different size and in differentrelative locations without departing from the principle of the inventionor sacrificing its advantages.

We claim:

1. Means for educting a uniform mixture of compressed liquefied gaseshaving diiferent vapor tensions from a pressure vessel container,comprising; an eductor within said vessel having an inner and outerchamber formed by a tube enclosed in a concentric jacket member, saidjacket member being spaced from said tube to provide in said outerchamber a capacity substantially twice that of said inner chamber; meansconnecting the inner chamber provided by said tube with the outlet ofsaid vessel; vertically spaced outlet openings in the otherwiseimpervious wall of said jacket member, and fluid communication betweenthe inner and outer chamber in the lower end of said tube.

2. Means for educting a uniform mixture of compressed liquefied gaseshaving difierent vapor tensions from a pressure vessel container,comprising; an eductor within said vessel having an inner and outerchamber formed by a tube enclosed in a spaced jacket member; meansconnecting the inner chamber provided by said tube with the outlet ofsaid vessel; inlet openings in the otherwise impervious Wall of saidjacket member in vertical logarithmic position with the distance betweenadjacent openings increasing from the bottom upwardly; and fluidcommunication between the inner and outer chamber at the lower end ofsaid tube.

3. Means for educting a u rm mixture of compressed liquefied gaseshaving different vapor tensions fl a pressure vessel container,comprising; an educter within said vessel having inn and outer chamberformed by tube enclosed 1 spaced jacket member; means connecting theinner chamber provided by said tube with the outlet of said vessel;vertically spaced inlet openings in the otherwise impervious wall ofsaid jacket member, and fluid communication between the and outerchamber at the lower end of said tube; the construction and arrangementof the being such that the pressure drop through the opening in thelower end of said tube is sufficiently low to drain substantially all ofthe liquid from the outer chamber during eduction, and the pressure dropthrough the openings jacket is su ficiently high so he liquid e teringthem cannot completely outer chamber during eduction.

An eductor, for einoving a uniform miX ture of two or more liquefiedgases from a cylinder in which they are under pressure, comprising; anupper tube having the upper end thereof secured in the outlet of saidcylinder; an inner tube ha the upper end thereof se cured in the lowerend of u'oper tube, and the lower end thereof adjacent e bottom of saidcylinder; an outer tube spaced from and coextensive with said inner tubewith the upper end thereof secured around the lower end of said uppertube; means closing lower ends of both said inner tube and said cutetube; said inner tube being provided with an inlet adjacent the lowerend thereof; and outer tube being provided with a plurality ofvertically spaced inlets.

5. The invention defined by claim 4; in which the cross-sectional areaof the said interior tube is somewhat greater than that of said outlet.

6. The invention defined by claim 4 in which the area of the inletopening in the said inner tube is substantially the same as thecross-sectional area of the interior thereof.

'7. The invention defined by claim a in which the cross-sectional areaof the annular openbetween said inner tube and said outer tube issubstantially twice the cross-sectional area of A interior of said innertube.

8. The invention defined by claim l in which the combined area of theinlets in said outer tube is substantially than the area of the inlet insaid inner tube.

9. The invention defined by claim 4 in which upper tube is bendable andis capable of g bent to position the lower end of the educ- 1G. Theinvention defined by claim 4 in which said outer tube is provided withseven inlet openngs with the lowermost substantially at the bottom ofsaid outer tul e, and the spacing between said openings is logarithmic.

11. An eductor, for removin a uniform mixure of two or more liquefiedgases from a cylin- E l which they are confined under pressure, .sing;two ch bers connected by a suitl-r e opening adjacent the bottom of saidcylinone of chambers being provided with a suitable connection betweenthe upper end thereor" and th outlet of said cylinder, and the other ofchambers being provided with a plurality of vertically spaced inletopenings, the spacbetween said openings being logarithmic and upwardlyprogressing.

JOHN N. BURDICK. ERIC SONHVIER.

